Method of making well screens



D OF MAKING WELL SCREENS Filed NOV. 25, 1927 i i in IL )1 UUUU uu ag-'4 U I I I2 I 000; M000 mm 001mg M WW 0000!] WWW [Hill/ 050!] MIMI/ 000!]! Mum/1100011 Mm 00/100 a 000!] 1' W000 W00 00000 i By 99mm 29, 19 9m 9,4 9,4 0

1 for-re egs.

Patented Apr. 14, 1931 EDWARD EJOHNSON, OF ST. PAUL, MINNESOTA METHOD OF MAKING WELL SCREENS Application filed November 25, 1927. Serial No. 235,551.

My invention relates to methods of making well screens and an object is to provide for making a well screen from a strip of sheet metal such as brass or other metallic substance not liable to corrosion by first perforating the strip at a multiplicity of places along its length, winding the perforated strip spirally into tubular form and securing together the edges of the strip which are j uxtaposed during the winding operation. I .am aware of the fact that it is old in the art to make a well screen from a strip of metal having a groove adjacent one edge thereof with perforations through the material forming the back of the groove, the strip having a flange adjacent its other edge and the strip being wound up spirally into tubular form with the edges overlapping in such manner that the groove at one edge and the flange at the other edge are interlocked with each other. Such method is disclosed in my Patents No. 899,054. dated September 22, 1908, and No. 1,287,031 dated December 10, 1918. I am also aware of the fact that it is old in the art to make a well screen by providing a perforated metal pipe which constitutes an inner shell and then winding thereon spirally, a metal ribbon composed of a number of strands or wires secured together in parallel relation with crevices between the individual strands so related to the perforations that passageways are produced through the composite structure. Such method is disclosed in my Patent No. 1,040,342 dated October 8, 1912. However, so far as I am aware, it is new to make a well screen by perforating a flat strip of sheet metal at a multiplicity of places along its length, winding the perforated strip spirally into tubular form with 49 its edges juxtaposed and non-overlapping and securing the juxtaposed edges together with application of heat to produce a well screen which is in effect integral'throughout so as to be self-sustained and not require 5 any supporting inner shell or rods.

he full objects and advantages of m invention will appear in connection with the detailed description thereof, and the novel features of my inventive idea will bep'articularlypointed out in the claims.

In the accompanying drawings which illustrate successive stages in the manufacture of my well screen,

Fig. 1 is a plan View showing a blank piece of sheet metal from which the well screen is made. Fig. 2 is a plan View showing the piece of sheet metal after it has been provided with a multiplicity of perforations. Fig. 3 is a side elevational view showing the tube produced by winding the strip spirally and securing together the juxtaposed edges. Fig. 4 is a side elevational view showing the tube after it has been finished by cutting oil the ends to make them square. Fig. 5 is a fragmentary view in section on the line 55 of Fig. 4: on an enlarged scale.

In carrying out my invention, blanksof the desired width and length are cutfrom sheet metal, one of these blanks being indicated by the numeral 10 in Fig. 1. This blank while still in flat condition is then provided with a multiplicity of perforations 12 by a cutting or punching operation. In the embodiment shown, the perforations 12 are arranged in groups of five transversely of the strip but it will be understood that the number of perforations transversely may be varied as desired. The perforations are preferably of elongated form to constitute slots and are proferably beveled as shown in F 5 so that when the tube is formed, the perforations will be enlarged inwardly whereby any particles that may pass in with the liquid will notbe retained in the perforations but will escape at the inside, thus preventing liability of the perforations becoming clogged. I111- perforate spaces indicated at l lJare left between successive groups ofperforations in order to give adequate strength to the finished article and imperforate spaces 16 are left at 90 the sides of the strip in order that the side edges may be secured firmly to each other after the strip has been wound up spirally as shown in Fig. 3. The strip after being perforated is wound up spirally in tubular form y in any suitable manner as by'wrapping it spirally around a mandrel with the edges close together but not overlapping each other. 'As shown in Fig. 5, a slight space may be left betweenthe juxtaposed edges for receiv- 's'trip'js-piral'ly into tubularfcrni' W-it h'its edges a inxt'apojs'ed and eparatedibya-sii ts am 1 f I V adaptedt re eivejaflugappi in thsflax v and welding-"saidl iXtaposed edgesftogethelf I ing' a After the. periferated strip has been-'wo ind up, the juxtaposed edges are secured together'by welding or soldering with the applicati'onof heat so that in efiect they are integrally'pnitedl, 'Unperfo'rated spaces 18 are leftatthe endsof'tlie strip sothat after--thei{stripjhas been wound up and itsedgesi' seciired.together in. the manner "just stated, portions'20 may becutoff as indicated onthefdottedlineflz Fig.3 to'. provide square ends forthe'finislied tnbular's'creen The carrying out-Ofmy processes alco veset forth results in. the production from a flat strip of sheetinetalofawellscreen which is.-

istriip while in fiat condition with a mnltiplic- I ity of perforations ofzthefsizedesired for g the finished article, winding said perforated strip spirally into'tubular form with its edges juxtaposed 'an'd non-overlapping, welding said; juxtaposed edges together'to produce a Well screen in which said edges arein effect integr'ally'nnited; and trimming off the ends 7 of the tubeithus-eforined to makelthe ends square r j IntestimOnyflvitliererif hereunto afi 3" 'I'EDW R D E. JOHNs' N;

signature;

in'efiect integralthroughoutand is self-sns- 7 tained-V sofasnotit o reqn'ire the addition of ny sustaining-en supporting means to hold it in the proper tubular shapeqf'Myprocess is articularly applicable for: use in making Well screens-"constructed from comparatively fthicks'hee t metal for inaking screens haying heavy walls. With: such material; it is-not practicableto produce the perforatiqns after the Striphas beenwound u-p' spirally; V The sequence 'qf steps is, therefore, an "imper'tant featureo f the inyention in regard t o the fact that thfflat'stllp should b'e'perforated be- ;"fore it iswonnd up} Perforationswhich slant 7 "from one sideef themetal te-the other'side can be sh'aped'te niuclrbett'er advantage while the stripfli's fl'atq While I may employ either electric Welding :or acetylene Welding, I have 1 found ing-pr' ac'ticethat:theflatter manner of 7 aiding in whicli an "acetylene torch-v iseln ployed; inveryeificient."

llclaimza;

' 1. The process' ofimaki'ng Well screen-s which consists in providing asingle strip 0fsheetmetal,of sufficient thickness to fo'rinja l; V

, 4'0 iself s'ustaiiiing Well screen,- proyiding said strip 'While' iii-flat condition ivith ainiulti'plic jit'yof perforatibns of thesi ze desiredfor the finished artidewindin said'perforated strip s irallyfi nto tnbular form-wimits edges f juxtapo ed and no'n-{eve'rlapping fand weld ingsaid juit'f pos ed'edgesgtogether tofj'pr l g g duce aiwellscreen inWhichsaidiedgesfare in self-siistai 'fstripjwhilein' flatcendition with a -ninltiiplic-j ity' 'gfperferations'of thesizedesiredfqrithe 1 effect integrally nnitedZj 2L, Thelproces's of 1 making Well screens Which consists in iprovi'di ngasingle strip of" I V 'l fjjisiifiicientthickness to'form' a sheet, "m

finished article,f"-winding" said perforated t6 producea we11.;screen in Whicliftsaiid ed e-s The recess of making, Well screens v dll sl ts i'n 'prOVidiin-g'a' strippf' .1; siqiiqrma mag weIP'scieen, prbviding' said 

